Self-Ballasted Wood Structure for Shoreline Protection and Aquatic Habitat Enhancement and Method of Manufacture

ABSTRACT

The present invention is a self-ballasted wood timber to be used for shoreline protection and aquatic habitat enhancement. It is made by installing a dense ballast material within an interior cavity of a wood timber. The material is retained within the timber by plugging the open end(s). Two or more self-ballasted timbers may be assembled to form larger structures. Structures composed of the present invention have the advantage of being composed of organic materials ballasted internally by a dense material with specific gravity relative to fresh or salt water greater than one. Thus they can provide all of the aquatic habitat enhancement benefits of natural organic materials without the buoyant instability associated with organic materials in dynamic aquatic environments. Additionally, they can provide stability for shoreline protection without the negative impacts to aquatic habitat, water quality, and natural water body aesthetics associated with inorganic shoreline stabilization structures.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX

Not Applicable.

BACKGROUND OF THE INVENTION

Development of land located adjacent to bodies of water, while beneficial for many reasons, can also result in undesirable negative impacts to both the property owner and the environment. Erosive forces due to the hydraulic action of water and sediment can impact the property owner by eroding and damaging land and property, while removal of logs, brush, and native vegetation material from within the water body and shoreline can exacerbate these problems as well as contribute to degradation of aquatic habitats through loss of cover, sedimentation, and degradation of water quality. If not addressed, over time, a substantial amount of property and aquatic habitat may be lost.

Both shoreline protection and aquatic habitat enhancement technologies have been described in the art. U.S. Pat. No. 607,215 A (Carson 1898) describes the use of riprap (stone) to protect the shore or bed of a stream, take, or ocean from scour. More modern accounts describe the use of concrete, masonry, gabion, and polymeric materials used to construct block unit retaining wall structures along shorelines (U.S. Pat. No. 7,198,435 B2, NM, Inc. 2007 and U.S. Pat. No. 8,689,501 B2, Inoxys S. A. 2014). Others describe the use of manufactured flexible fabric turf reinforcement mats (U.S. Pat. No. 7,950,878 B2, Erosion Tech, LLC 2011). While these methods may provide some degree of immediate, local shoreline protection, they utilize hard, inorganic, and/or uniform materials which can negatively impact the habitat complexity that aquatic organisms rely on for survival. They may also decay or become dislodged, resulting in permanent toss of shoreline protection materials and release of polluting materials to natural waters. Furthermore, relatively smooth (low surface area), hardened, biologically inert materials often replace rough (high surface area), soft, self-replenishing organic materials such as wood and vegetation. Thus, they do not “self-heal” after damage or persist as long in a functional capacity nor absorb as much hydraulic force, and erosion inducing energy is often reflected to other locations along the water body's boundaries.

Disclosure of aquatic habitat enhancement devices can be found in U.S. Pat. No. 5,272,829 A (Roberts & Schulyer 1993), U.S. Pat. No. 5,823,710 A (Silverbrook Limited 1998), U.S. Pat. No. 6,505,446 B1 (Mccrary 2003), and U.S. Pat. No. 8,020,515 B2 (Metzler 2011), U.S. Pat. No. 5,272,829 A describes an artificial tree stump used to attract fish, white U.S. Pat. No. 8,020,515 B2 describes individual strands of a plastic buoyant material attached to a weight. These devices and others similar are not intended for shoreline protection, however, and the materials proposed may result in pollution of natural waterways.

U.S. Pat. No. 5,823,710 A describes an engineered structure composed of multiple logs joined together with spars to form a larger, hollow, cylindrical log-like structure that can be ballasted with rock on its interior. This structure, however, is composed of multiple logs and cannot be scaled easily to fit the complex contours of a natural water body. Thus, acting by itself or in multiple units, this structure cannot be used effectively for shoreline protection in many cases where the scale of the shoreline heterogeneity is on the order of the size of a single log or smaller. Its engineered appearance may also present aesthetic concerns within natural water bodies.

U.S. Pat. No. 6,505,446 B1 describes a cast concrete simulated log having an outside surface simulating a natural log in appearance and a single rebar reinforcement feature. The cast concrete logs can be assembled into larger structures or used individually to simulate large woody material (LWM) aquatic habitat. This device, however, presents some of the same problems posed by bank protection methods described in the art. For instance, the simulated concrete log is only log-like in appearance. Thus, the hardened concrete logs do not exhibit the same energy absorption properties of softer natural wood materials. Concrete also does not provide an ideal medium for the growth of vegetation or other organisms. Additionally, materials used to construct this device may not be aesthetically acceptable within natural water bodies and may also present polluting materials to natural waters.

Organic material of all sizes is generally recognized as important for maintaining the biotic and abiotic functions of aquatic environments. Large woody material, however, is recognized as being critical. It has a major influence on water body boundary form, sediment transport and deposition patterns, as well as organic cycling and aquatic habitat formation. Woody material has also been recognized as a desirable alternative to rock and other methods of shoreline and property protection. For instance, as far back as 1898, U.S. Pat. No. 607,215 A described wood as a desirable alternative method to rock rip rap back protection. U.S. Pat. No. 7,198,435 B2 has described the use of landscape and railroad ties for shoreline protection. Wood is a buoyant material, however, and requires a suitable ballast material or “sinker” in order to stay in place within the dynamic aquatic environment. Therefore, it is clear that there is a critical need for a non-buoyant product capable of being used for shoreline protection that also emulates all of the characteristics of natural wood material critical for maintaining and improving aquatic habitat and natural water body aesthetics. Furthermore, it is desirable for product to persist in the aquatic environment for a long period of time before decaying into constituents which are not foreign to the water body in which they are present. It is also desirable for this product to self-recruit its replacement(s). The present invention meets these specifications and combines the benefits of native aquatic materials with engineered features to reduce buoyancy and improve reliability and suitability for shoreline protection as well as aquatic habitat enhancement applications.

BRIEF SUMMARY OF THE INVENTION

In a preferred embodiment of the invention, a natural wood timber with or without bark, branches, and/or rootwad intact is provided and a cavity is made along the longitudinal axis of the timber. The cavity is then filled with a sufficient quantity of stone, sand, or other similar material to increase the specific gravity (relative to fresh or salt water) of the unit to greater than one (1). A wood or similar material plug is then inserted over the cavity end(s) to retain the material. The completed invention constitutes a self-ballasted wood structure unit composed of materials native to natural water bodies which may be used for aquatic habitat enhancement and shoreline protection.

In another embodiment of the invention, a natural wood timber with or without bark, branches, and/or rootwad intact is provided and a cavity is made along the longitudinal axis of the timber. The cavity is then filled with a sufficient quantity of concrete to increase the specific gravity (relative to fresh or salt water) of the unit to greater than one (1). A wood or similar material plug is then inserted over the cavity cricks) to retain the material.

In other embodiments of the invention, the plug inserted over the cavity end(s) to retain ballast material may be constructed of concrete, stone, or other similar material.

In another aspect of the invention two or more self-ballasted wood structure units are installed together to create larger and more complex structures and/or ballast other buoyant materials. The completed structure, composed of individual self-ballasted wood structure units, may be used for aquatic habitat enhancement and shoreline protection.

Advantageously, materials used to construct self-ballasted wood structure units can be found at the point of installation or transported from a nearby source. Units may be assembled on or off site. Advantageously, units can be placed from the bank without the need for dewatering or construction equipment or personnel located within the water body. Thus negative impacts and economic costs due to construction are reduced or eliminated.

Advantageously, the present invention can be scaled to fit any water body or shoreline and can be assembled together to form larger, more complex structures and/or ballast other buoyant materials. Such structures provide a large quantity of surface area and interstitial space utilized by aquatic organisms. Additionally, the present invention and structures composed of the present invention can be used to redirect hydraulic forces due to the action of water and sediment and reduce negative impacts to land and other property. Redirection of hydraulic forces can also be used to scour pools and sort sediments critical to rearing and spawning habitat for some aquatic organisms.

Advantageously, the present Invention can be constructed entirely from materials native to natural water bodies. Thus, decay of the invention over long periods of time does not result in the release of foreign, polluting materials to natural waters.

Advantageously, the present invention, white not buoyant and thus unstable within aquatic environments, is constructed on its exterior from natural wood material in its native state. Thus, it is indistinguishable from natural wood material to the human eye and behaves similarly to un-ballasted, natural logs to provide a growing medium for vegetation and other organisms. Therefore, the present invention self-recruits its replacements by providing a suitable substrate for the growth of vegetation and/or accumulation of new sediment and large woody material. Furthermore, it's soft, rough, irregular, and high surface area exterior provides superior energy absorption characteristics, reducing erosive forces before they are able to act upon shorelines and other property.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 a is a cross section view from 1 b of a self-ballasted timber with ballast material installed according to one embodiment of the present invention.

FIG. 1 b is a perspective view of a completed self-ballasted timber with end plug installed according to one embodiment of the present invention.

FIG. 2 illustrates an arrangement of completed self-ballasted timbers according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In a one embodiment of the present invention, referring to FIGS. 1 a and 1 b, a natural wood timber (3) with or without bark, branches, and/or rootwad intact is provided and a cavity of an appropriate diameter and length is made along the timber's longitudinal axis. The cavity is then filled with a sufficient quantity of stone, sand, or other similar material (2) to increase the specific gravity (referenced to fresh or salt water) of the combined wood/ballast material unit to greater than one. It is known to the inventor that the length and diameter of the cavity must be sized appropriately to accommodate an appropriate quantity of ballast material and that an appropriate quantity of ballast material is dependent upon the density of both the ballast material and the wood. It is also known to the inventor that the thickness of the wood remaining around the cavity must be sufficient to prevent the timber from breaking or fracturing under the weight of the ballast material. These requirements can be addressed by a person skilled in the art based on the characteristics of the particular wood and ballast materials utilized. A wood or similar material plug (4) is then inserted over the cavity end(s) to retain the ballast material. The plug may be fastened to the timber by friction, metal nails, screws, bolts, epoxy glues, or any other means (not shown) known to those skilled in the art.

FIG. 2 illustrates an arrangement of self-ballasted timbers (1). Any number of timbers (1) may be arranged together to form various structures. Any number of self-ballasted timbers (1) can act as an anchoring device when affixed to any number of un-modified logs or wood material (not shown. Self-ballasted timbers (1) alone or in combination with any number of un-modified logs or wood material will provide the following benefits:

-   -   1. Create and enhance a wide variety of aquatic habitats;     -   2. Protect shorelines and other property from scour and erosion;         and     -   3. Provide structure and foundation for aquatic structures such         as piers, monitoring stations, and buoys.

Advantages of the self-ballasted timbers are as follows:

-   -   1. Can be constructed entirely from materials native to natural         water bodies. Thus, decay of the invention over long periods of         time does not result in the release of foreign, polluting         materials to natural waters;     -   2. Ballasting material is securely contained within the interior         of the woody material. Thus, ballast material cannot be scoured         or removed from the wood material and the wood material is not         buoyant and cannot float away;     -   3. Indistinguishable from natural wood material to the human eye         and behaves like un-ballasted, natural logs to provide a growing         medium for vegetation and other organisms.     -   4. Can self-recruit its own replacements by providing a suitable         substrate for the growth of vegetation and/or accumulation of         new sediment and large woody material;     -   5. Can provide a large quantity of surface area and interstitial         space utilized by aquatic organisms;     -   6. Can sort sediments, scour pools, and generate new habitat for         aquatic organisms;     -   7. Can provide superior energy absorption and re-direction         characteristics, reducing erosive forces before they are able to         act upon shorelines and other property;     -   8. Can settle into scour holes without toss of function;     -   9. Can be constructed from materials found on site or         transported from a nearby source;     -   10. Units can be placed from the bank without the need for         dewatering or construction equipment or personnel located within         the water body; and     -   11. Can be designed, scaled, and configured to address a         specific location or a particular need(s).

Sequence Listing

Not Applicable.

It will be apparent to the skilled artisan that there are a broad variety of alterations that may be made in the several embodiments of the present invention taught herein, Without departing from the spirit and scope of the invention, the invention is to be limited only by the claims which follow. 

What is claimed is:
 1. A self-ballasted wood timber with a cavity within its interior which is filled with a ballast material with specific gravity (relative to fresh or salt water) greater than one.
 2. The self-ballasted wood timber of claim 1 where the ballast material is composed of stone, sand, concrete or other similar material.
 3. The self-ballasted wood timber of claim I wherein a plug composed of wood, stone, concrete, or similar material is inserted over the cavity end(s) to retain the ballast material.
 4. A structure comprising two or more self-ballasted timbers of claim 1, each having a cavity within its interior which is filled with a ballast material with specific gravity (relative to fresh or salt water) greater than one.
 5. A method for forming a self-ballasted wood timber unit comprising: (a) Providing a wood timber and excavating a cavity along its longitudinal axis; (b) Filling the excavated cavity with a ballast material with specific gravity (relative to fresh or salt water) greater than one; and (c) Inserting a plug over the cavity end(s) to retain the ballast material. 